The broad, long-term objective of this proposal is the creation of a pediatric injury circumstance scoring system for use in pediatric trauma triage, care and research. Central to achieving this objective is the development of a new research approach, Biomechanical Epidemiology; the concurrent application of the principles of biomechanics and engineering to an injury control research problem. Current measures of injury severity used for injury prediction in the acute care setting utilize physiological and clinical parameters that vary over time and have limited ability to predict occult injuries. It is hypothesized that pediatric injury prediction can be improved by incorporating variables describing the injury circumstances (e.g., speed and direction of impact) into the physiological measures. In this research project a pediatric Injury Circumstance Evaluation tool, the ICE Survey for pedestrians and bicyclists, will be developed, administered and correlated with clinical outcome to create the ICE Score. Potential applications for the ICE Score include: triaging and formulating care plans in the pre-hospital and acute care settings; adjusting case mix for purposes of research or performance evaluation testing; validating biomechanical models of injury; and evaluating preventive initiatives. As a byproduct, this research will bring together injury researchers with backgrounds in pediatrics, surgery, epidemiology, statistics and biomechanics. The specific aims of the project are: 1. to incorporate biomechanical and epidemiological principles into the formulation of the ICE Survey; 2. to pilot test refine, and administer the survey and evaluate its use in a pediatric acute care setting: and 3. to create the ICE Score from survey responses that predict actual physical damage to the child. The research design is a prospective study for score development. Steps in score development include: 1. survey construction based on epidemiological and biomechanical data on injury occurrence: 2. administration of the survey to pre-hospital care providers, witnesses, relatives, and the injured child after pedestrian and bicycle- related injury events; 3. review of survey performance using professional reconstruction of injury events as the "gold standard": 4. modification of survey design to accommodate observed limitations in reliability; and 5. correlation of survey responses with actual measures of physical damage to the child in the form of the Injury Severity Score and the Abbreviated Injury Scale (AIS-90) and creation of the ICE Score. In a future study, a multi-centered trial will validate the ICE Score in predicting pediatric physical injury.